Ballard Street Name Mosaic Preservation Project

Map of Mosaic and Metal Text Locations, 2016

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Ballard Street Name Mosaic Preservation Project

Map of Mosaic and Metal Text Preservation Sites, 2005 to 2016

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Ballard Street Name Mosaic Preservation Project Table of Contents

Download this document, Historical Appendix, GIS files & Data Table: http://www.bensonshaw.com/bensonshaw.com/BallardTiles_Preserv2.html

Photo Survey - Available on request. b33@bensonshaw.com

Map  of  Mosaic  and  Metal  Text  Locations,  2016   2  Map  of  Mosaic  and  Metal  Text  Preservation  Sites,  2005  to  2016   3  

Project  Overview   5  A. Goals  and  Components   5  B. Street  Name  Mosaics  –  Description  &  Brief  History   5  

I. Preservation  SpeciBication   6  A.  General   6  B.  Saw  Cutting   6  C. Salvage  and  secure  storage   7  D. Resetting  -­  General  Conditions   7  E. Resetting  -­  Fresh  Set  Option   8  F. Resetting  -­  Blockout  Option   9  

II. Short  term  protection  and  restoration   10  A. Work  zone  for  in  situ  work   10  B. Cleaning   10  C. Treatment  of  Cracks  and  Joints  through  tiles  and  substrate   10  D. Replacement  tiles  -­  materials   10  E. Replacement  tiles  -­  Set  &  Grout   10  F. Join  parts  of  mosaic  separated  by  joint  or  crack  -­  offsite  restoration     11  

III. New  and  Replacement  Mosaics   12  A. General  Mosaic  design   12  B. Net  the  tiles   12  C. Setting  option  A  for  new,  netted  mosaics  -­Shallow  Recess   13  D. Setting  Option  B  -­  Fresh  set  a  netted  mosaic   14  

IV. Materials:  sources  and  information   15  A. Early  1900s  Replacement  Tiles   15  B. Mid  1990s  Replacement  Tiles   15  C. Tiles  for  new  mosaics   15  D. Thinset  mortar  for  tile  setting   15  E. Tile  Grout  –  sanded  polymer  enhanced  exterior   15  F. Transition  Grout  for  blockout  setting   15  G. Tile  and  Grout  Sealer   15  H. Epoxy   15  

V. Existing  Conditions  and  Sections   16  A. Early1900s  Mosaics   16  B. 1990s  Mosaics   16  C.  Relocated  mosaics   17  D. Replacements  and  New  Mosaics   17  

VI. Condition  and  Preservation  Examples     18

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Ballard Street Name Mosaic Preservation Project Project  Overview  

A. Goals and Components • Recognition of the mosaics in regional and City of Seattle planning,

permitting and development processes. • GIS files with mosaic locations and related data for inclusion in SDOT

and other City and regional GIS portals. • Photo archive and historic information documenting the entire

collection of street name mosaics in Ballard. • Preservation guidance and specification for use by permit applicants

permit reviewers site work personnel and field verification by SDOT and DCI inspectors.

• Restoration guidance and specification for new mosaics. • Research and reporting of mosaic history and preservation.

B. Street Name Mosaics – Description & Brief History Blue and white tile mosaics displaying historic City of Ballard street names are embedded in concrete sidewalks at more than 50 locations in the Ballard Neighborhood of Seattle. The streets were named during City of Ballard platting in the late 1800s and early 1900s. Ballard’s streets and avenues were renamed after annexation to City of Seattle in 1907. Ballard’s street name mosaics were established during two distinct historic periods. 32 older mosaics, most along 20th Ave NW were part of concrete sidewalk construction undertaken by City of Ballard starting circa 1903. Another group of 22 mosaics was installed as a community project in the mid 1990s in existing sidewalks along 24th Ave NW. Several other new mosaics were added in the 2010s. Embedded bronze text street names from circa 1905 are evident at 4 locations. Future community and private projects may create additional street name mosaics in same format. A project is currently envisioned to restore the Ballard mosaics in worst condition and replace missing ones. The Ballard community regards these mosaics as significant cultural assets. They must not be discarded, no matter their condition. A few, isolated mosaics in same format are present in other Seattle neighborhoods. Preservation and restoration guidance provided in this document applies specifically to the Ballard mosaics, and may be appropriate for the other mosaics found elsewhere in Seattle and surrounding communities. The History Appendix to this document offers a more detailed description of the mosaics and the City of Ballard. View and download GIS shape files, maps, History Appendix and other project information: http://www.bensonshaw.com/bensonshaw.com/BallardTiles_Preserv2.html Contact Benson Shaw regarding photo survey and other mosaic information: b33@bensonshaw.com

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Ballard Street Name Mosaic Preservation Project I. Preservation  SpeciBication  

A. General 1.Maintain the presence of every mosaic, at approximate same

location. 2. Mosaics in poor condition are to be preserved, not discarded. 3. Typical Preservation protocol: Saw cut the entire mosaic as a single, full

depth block from the existing concrete. Salvage and store the block in a secure location until construction of the new walk. Reinstall the mosaic at same location and orientation in the new sidewalk.

B. Saw Cutting 1.Avoid damage to the tiles during cutting and subsequent handling. 2.Use wet cutting equipment of sufficient power and blade diameter to

thru-cut the existing concrete, typically 4” to 6” thick. 3.Cut through sidewalk to allow removal of the mosaic as a single, full

depth block with rectangular face, or as multiple blocks if the mosaic is broken by cracks or joints in the existing walk.

4. Standard offset: 0.5” min, 1.0” max. outboard of the mosaic perimeter. Cut parallel to edges of mosaic.

5. Conditional offset: Greater offset is required if mosaic is not rectangular or if tiles are not aligned in straight edges.

a. Cuts shall produce a rectangular block. b. Offset from non-straight edges shall be 0.5”(min) to 1.0”(max).

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Standard OffsetMosaic tiles are aligned

Sawcut 0.5" min, 1.0" maxTyp all 4 cuts

90.00° typ

IB 4

Conditional OffsetMosaic tiles are not aligned

Sawcut

90.00° typ

1/2" min, 1" maxTyp @ max deviation

Joint or crack

Missing tiles

IB 5

Ballard Street Name Mosaic Preservation Project C.Salvage and secure storage

1. Record existing position and orientation of mosaic prior to removal. 2. Mosaic concrete is not steel reinforced. Handle gently. 3. Avoid damage to the cut edges while lifting mosaic block from

surrounding surfaces and during subsequent handling. 4. Store mosaic in secure location to prevent loss, theft and damage.

Note: at least one mosaic was stolen while stored on-site. 5. Document the secure storage and transmit location to SDOT inspection

team. 6. Restore mosaic if condition is 4 or below (see GIS data table). See Short

Term Protection and Restoration section below. 7. If off site restoration is elected and new concrete sidewalk is placed

prior to completion of restoration, provide a properly sized blockout in the new concrete.

8. Recover any loose tiles & deliver to project conservator or restoration professional. See Short Term Protection and Restoration section below.

D. Resetting - General Conditions 1. Thicken new concrete under mosaic location. 2. Provide rebar ring or WW mesh reinforcement around mosaic. 3. Set surface of mosaic flush with surrounding new concrete. 4. Mask mosaic and border to protect from slurry. 5. Match recorded position as closely as possible. Usual position is

centered on walkway centerline and centered in 24” score pattern. 6. Avoid placing a mosaic against or across a construction joint in the

concrete. OK to place mosaic across decorative scoring. 7. Match recorded orientation. Generally the text appears “right side up”

when viewed with mosaic between the viewer and the named street. 8. New location and orientation if existing is unknown:

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SAMPLE. STSAMPLE. ST

NW ANY St

SA

MP

LE A

ve N

W

EqEq

ANY.ST

Edge of intersecting walk6" min

Location & Orientation if orig unknownAlt Score Pattern NTS

10" max

SAMPLE.A V

E

Thicken new concrete.Typ under all reset mosaics.

ID 8b

SAMPLE. STSAMPLE. ST

NW Any St

SA

MP

LE A

ve N

W

EqEq

Intersecting walk

Eq

Eq

Plantin

g

Area

Location & Orientation if orig unknown24" Score Pattern NTS

ANY.ST

SAMPLE.A V

E

Note: Avenue mosaics arepresent at only a few locations

Thicken new concrete.Typ under all reset mosaics

ID 8a

Ballard Street Name Mosaic Preservation Project E. Resetting - Fresh Set Option

1. Prepare sub grade for new sidewalk including excavation for thickened concrete at intended mosaic location.

2. Pour new walk, screed and perform initial finish work. 3. Mask mosaic surface to prevent slurry penetration into grout lines. 4. Excavate fresh concrete volume equivalent to mosaic block at point of

installation. Reasons: Mosaic will not need excessive force to attain flush condition. Surrounding concrete will not bulge or crown from additional volume of mosaic.

5. Press mosaic block into excavated depression until flush with surrounding.

6. Embed rebar ring around mosaic area. 7. Spot finish around mosaic as needed. 8. Float and broom surrounding surface as required. 9. Tool/score edges and joints as required. Suggest no tooling around

mosaic. 10.After concrete is hardened and walkable, remove mosaic masking

and clean as necessary.

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Reset Mosaic, Fresh Set OptionSection

Rebar Ring - (1) #3 min2" min clear all sides

2" clear

New concThicken under mosaic

Mosaic blockSawn from exist walkeq

eq

IE all

Ballard Street Name Mosaic Preservation Project F. Resetting - Blockout Option

1. Prepare sub grade for new sidewalk including excavation for thickened concrete at intended mosaic location.

2. Create void in new concrete with foam, lumber or other material which can be removed after concrete is hardened.

3. Face dimension of void is equal to mosaic block plus 1/2” all sides. 4. Depth of void is max thickness of mosaic block plus ½” min. 5. Tooling (aka shine) around blockout is not recommended. 6. If mosaic installation is not concurrent with blockout removal,

temporarily cap the void flush with new concrete surface. Suggest 1” concrete , over sand filler. Remove concrete and sand cap at time of mosaic installation.

7. Install mosaic in void: a. Place grout setting bed in bottom of void, eg Duragrout mixed

very thick. b. Press mosaic block into grout until flush with surrounding and

centered in void. c. Fill remaining void with thick grout. d. Trowel top of void & clean mosaic as necessary.

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Reset Mosaic, Blockout OptionSection

Rebar Ring - (1) #3 min2" min clear all sides

New concThicken under mosaic

Transition grout1/2" typ, (4) sides & bot

Mosaic blockSawn from exist walk

0.5"2" clear

0.5"

eqeq

Blockout new concreteto accept mosaic.

IF all

Ballard Street Name Mosaic Preservation Project II. Short term protection and restoration

Mosaics at several locations will benefit from restoration to survive in good condition until the surrounding sidewalk is replaced. A community based project is envisioned to perform this work. For any mosaic salvaged from an existing walkway and which is assigned condition rating of 4 or lower, off site restoration is recommended during the storage period. Material and tradework processes required for in-situ and off-site restoration of mosaics are described here:

A. Work zone for in situ work 1. Provide cones, barricades, etc. as needed to protect public and

mosaic. Pedestrians must be able to pass safely.

B. Cleaning 1. Scrape gently to remove gum. Avoid products that freeze the gum. 2. Scrub/brush with 3:1 water/bleach or moss remover. 3. Scrub/brush with bio degradable detergent (eg Simple Green) 4. Use alcohol and other solvents as nec. to remove paint. 5. Mild acid wash if needed to profile setting and grouting areas. 6. Baking soda rinse to neutralize bleach & acids 7. Clean water rinse. Dry as nec for tile and grout work.

C.Treatment of Cracks and Joints through tiles and substrate 1. Pressure wash or hand clean the joint to remove weeds, soil, etc. 2. Not to exceed 400psi. Do not blow out any tiles! 3. Remove dirt, etc to full depth of existing sidewalk, if possible. 4. Fill joint with Duragrout or equiv Non Shrink Grout to discourage weeds. 5. Fill joint in mosaic area and to at least 5” each side of mosaic.

D. Replacement tiles - materials 1. See Section  IV.  Materials 2. Provide tiles with material, size and color match. 3. Cut half and quarter tiles as nec. Wet grind to fit as nec.

E. Replacement tiles - Set & Grout 1. Apply in same pattern & spacing as surrounding, per photos and data. 2. Thin set or epoxy new tiles flush with surrounding tiles. Note: Thin set may

raise new tiles above flush. Wet grind back surfaces of new tiles to reduce tile thickness. Do not install above flush and grind down after setting.

3. Protect from use until fully set and grouted. 4. Grout between tiles after setting medium is stable. Protect surrounding

surfaces. Several grout materials are appropriate: a. Duragrout or other Non Shrink grout. Test for color match. b. Sanded tile grout with polymer additives. Test for color match.

5. Protect for 24 hr or until stable to anticipated loads, esp skate boards. 6. Clean and apply sealer after 21day cure. See Section  IV.  Materials.

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Ballard Street Name Mosaic Preservation Project F. Join parts of mosaic separated by joint or crack - offsite restoration

1. Clean and clear both faces of joint for proper mating of the parts. 2. Test clamp parts to straight bars to align mosaic in uniform surface. 3. Release clamps on one side. 4. Mix and apply epoxy to concrete faces. 5. Avoid application of epoxy to tiles. 6. Limit epoxy volume to prevent spread to tile surfaces during mating. 7. Mate the parts and reset clamps. 8. After epoxy setup, release clamps and remove the bars. 9. Clean mosaic surface and regrout between tiles with exterior rated

sanded tile grout. Test first for color match. 10.Apply sealer after 21day cure. 11.See Section  IV. Materials below for epoxy, grout and sealer options.

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Repair Mosaic at Crack or JointNTS

IIF

Ballard Street Name Mosaic Preservation Project III. New and Replacement Mosaics New mosaics can be created and installed to remedy locations where mosaics were removed and not replaced, and where relocation or restoration of an existing mosaic may be unattainable. Also, community or other entities may desire additional mosaics at new locations. This section provides guidance for creating and installing such new mosaics. Field tests of several material and technique options for new mosaics indicate that setting a netted mosaic provides best aesthetics and durability in both new and old walkways. See also Section V Existing Conditions and Section VI Examples of reset and new mosaics. The following specification describes the preferred processes and materials for creating and installing new mosaics.

A. General Mosaic design 1. New mosaics shall closely reproduce the design and format of the

existing mosaics. 2. Tile description per specification in Section  IV.  Materials

a. Material - unglazed porcelain with solid, thru color. b. Color - blue border & blue text on white background. No

substitutions. c. Size -¾” x ¾” x ¼” max. Net to match existing grid and grout

space. Larger tile is not acceptable. Glazed tile is not acceptable.

d. Acceptable grout space: 1/32” to 1/16”. 3. Mosaic Format - Replicate mosaic design and format per photos, field

examples, and specifications in

B. Net the tiles 1. Layout the tiles, face down, with consistent grout space, 1/16” max. 2. Net the tiles on back side per best trade practices. See also Section  IV.  

Materials. 3. Note: American Restoration Tile can provide a netted mosaic for a fee.

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Ballard Street Name Mosaic Preservation Project C.Setting option A for new, netted mosaics -Shallow Recess

1. Note: This is preferred option, producing best results. 2. Pour & finish walks. Cure to 21 days minimum. 3. Establish a rectangular recess in the new walk at correct location. 4. Dimension the recess to yield a grout space around the mosaic. 1/8”

min, ¼” max all sides. 5. Wet saw the perimeter and many cuts through interior. ¾” deep max. 6. Break away interior of recess with hammer and chisel. 7. Grout/screed bottom as nec to attain consistent depth for tile setting. 8. Set & grout mosaic per best trade practices.

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Preparing a shallow recess in existing walk. Wet saw perimeter and many interior cuts 3/4” deep. Chisel out interior.

Netted mosaic tilesThinset & grout

Section, Netted Mosaic in Shallow RecessNTS

Compacted earth

Exist concrete walk Saw/chisel shallow recessLevel bottom w/grout

Sawcut3/4" max

IIIC all

Ballard Street Name Mosaic Preservation Project

D. Setting Option B - Fresh set a netted mosaic 1. Notes:

a. This technique requires experienced trade work. b. Test offsite to gain understanding of best concrete stiffness to

accept the downward pressure without driving the mosaic below finish grade.

c. Mosaics installed circa 1905 during City of Ballard improvements were installed with this technique.

2. Prepare netted (aka bonded) mosaic. 3. Pour the new walk, screed, float, allow it to become firm 4. When concrete is firm, place netted mosaic in correct position. 5. Press netted mosaic into the surface.

a. Tamp gently with a wide trowel, or . . . b. Tamp gently with a screed board supported on form edges.

6. Slurry will fill the mosaic grout spaces. 7. Complete finish operations with best trade practice. Float, trowel,

broom & add scoring and edging to surrounding surfaces per sidewalk.

8. Do not “shine” or add decorative troweling at mosaic perimeter. 9. Wait for concrete to become firm enough that mosaic does not move

downward when tooled. 10.Trowel and wipe excess slurry to fill grout spaces and clean mosaic

surface.

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Netted Mosaic tilesPress into firm Concrete

Fresh Set New Netted MosaicNTS

Compacted earth

Fresh (wet) Concrete.Pour, Screed, Float, allow to become firm

IIID all

Ballard Street Name Mosaic Preservation Project IV. Materials: sources and information

A. Early 1900s Replacement Tiles 1. Original manufacturer unknown. 2. Replace with:

American Restoration Tile. restorationtile.com 501-455-1000 11416 Otter Creek South Road Mabelvale, AR 72103 Blue - Custom color match blueWhite - Custom color match white

B. Mid 1990s Replacement Tiles 1. ¾” tiles were cut from 12”x12” Fiandre tiles (discontinued) 2. Replacements and new mosaics tiles:

Crossville, Inc. 349 Sweeney Drive Crossville, TN 38555 Widely available at tile distributors and sales points. Acquire large tiles and saw them to ¾”± squares to fit. Blue tiles - Crossville Cross Color B180 Lapis Blue 12” x 12” White tiles - Crossville Cross Color A215 Empress White 12”x12”

C.Tiles for new mosaics 1. American Restoration Tile restorationtile.com 501-455-1000

Blue - Custom color match blueWhite - Custom color match white

D. Thinset mortar for tile setting 1. SilPro/Raeco Poly-Set Polymer Modified Thinset Mortar

Color - Gray widely available at tile and concrete supply venues Or equivalent exterior grade thinset

E. Tile Grout – sanded polymer enhanced exterior 1. Laticrete 1500 Sanded Grout www.laticrete.com

Color - #24 Natural Grey Widely available at tile and concrete supply venues. Or equivalent cementitious exterior sanded grout.

F. Transition Grout for blockout setting 1. L&M Duragrout or equivalent non-shrink grout. 2. Widely available at concrete supply vendors.

G.Tile and Grout Sealer 1. Prosoco Paver Enhancer WB or equiv water based penetrating sealer.

H. Epoxy 1. Any stiff epoxy, esp epoxy intended for anchor bolts in concrete. 2.Widely available at concrete supply vendors.

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Ballard Street Name Mosaic Preservation Project V. Existing Conditions and Sections

Several mosaic materials, substrates and installation processes are present in the Ballard sidewalks.

A. Early1900s Mosaics 1. Substrate is 3 1/2” concrete base course with 1/2” mortar topping. 2. Mosaics were fresh set in the mortar layer (mortar was still wet). 3. Tile source is unknown. Mosaics were probably paper bonded.

B. 1990s Mosaics 1. Volunteers of the Central Ballard Community Council created and

installed 22 mosaics along 24th Ave NW in existing walks of various age and composition.

2. Mosaics were netted and installed with thinset and grout in shallow recesses which were sawn and chiseled into existing concrete.

3. Tiles – 12” x 12” Fiandre tiles (discontinued) sawn into ¾” squares.

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Mosaic tilesFresh set

Historic Section, 1905 concretefrom City of Ballard Engineer's specification

3.5"

Mortar Course(1)Cement:(1.25)Sand

Compacted earth

Base Course - (1)Cement:(3)Sand:(6)Gravel.5"

VA all

Netted mosaic tilesThinset & grout

Section, mid 1990s mosaicsfrom observation during installation

Compacted earth

Exist concrete walk Saw/chisel shallow recessLevel bottom w/ grout

Sawcut3/4" max

VB all

Ballard Street Name Mosaic Preservation Project C. Relocated mosaics

1. Several mosaics were sawcut as full depth blocks from existing walks for resetting in new walks at or near same location.

2. They were reset in new concrete as fresh set or in a blockout. Several of these have sunk slightly and are no longer flush with surroundings. Thickened concrete under the mosaic location is recommended.

3. See Sections  I  E and I  F for recommended installation sections.

D. Replacements and New Mosaics 1. Several mosaics were discarded and replaced with new mosaics.

Several other mosaics were added at locations not previously hosting mosaics. Some were installed per Section  III  C. Others were precast.

2. Precast fabrication sequence (offsite): a. Netted mosaic placed face down in 2” deep form. b. Form face dimension is mosaic dimension plus 3/4” all sides. c. Duragrout, fluid consistency, poured over mosaic to fill the form. d. After setup, demold and turn face up. Rub in Duragrout to fill any

surface voids.

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Mosaic tiles

Section, Relocated Mosaics, 2005 and laterfresh set or set in blockout

Compacted earth

Saw cut from existing walkReset in new walk

New concrete walk

Note: Not recommended installation process.Some of these relocated mosaics sank after installation.See Sections)I).E.)and)I.F. for recommended installation.

VC all

New Netted mosaic

Section, New Precast Mosaics, 2005 and laterfresh set in new sidewalk

4"

Compacted earth

New concrete walkPrecast Duragrout block2"

.75" typ 4 sides

VD all

Ballard Street Name Mosaic Preservation Project VI. Condition and Preservation Examples

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Missing Tiles, adjacent open joint. • Brush/clean mosaic to remove grime

& organics per Section  II  B. • Clear the open joint, but do not fill. • Mask surrounds • Retile & grout

Mostly intact. Needs regrout. • Brush/clean mosaic to remove grime

& organics - Bio detergent then bleach, then light etch, then neutralize & dry.

• Mask/protect surroundings • Regrout

Open Joint. • Brush/clean mosaic to remove grime

& organics - Bio detergent then bleach.

• Clear grime/organics from crack. Pressure wash. 400psi max. Do not detach tiles.

• Mask & fill entire length of crack w/ non shrink grout.

Small Crack through mosaic. • Brush/clean mosaic to remove grime

& organics - Bio detergent then bleach, then light etch, then neutralize & dry.

• Clear grime/organics from crack. Pressure wash if nec. 400psi max.

• Tape around mosaic border • Grout & protect until walkable

Ballard Street Name Mosaic Preservation Project

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Shallow recess for netted mosaic •Diamond saw ¾” deep perimeter and several interior lines. •Break with chisel. •Install mosaic w/ thinset & grout, or in one step forcing it into structural grout. •Best technique. Highly recommended.

Precast mosaic, 2” thick. •Mosaic is netted with 1/16” tile spacing. •Layout mosaic face down in form. •Casting medium: Duragrout •Reset in blockout or fresh set. •Not recommended technique.

Mosaic saw cut from exist walkway •Full depth blockout in new walk. •Mosaic is mud set. •Cutting border is too wide. •Set too close to joint. •Slurry not cleaned from border. •Edge tooling is distracting. •Set too close to construction joint.

Mosaic cut from exist walkway. •Full depth blockout in new walk. •Mosaic is sand set with caulk edge. •Poor installation: The new concrete rolls, mosaic was set a bit low, caulk is delaminating, mosaic is sinking.